context managers and some decorators

python.html

@@ -1096,6 +1096,47 @@ Julio
 >>>     # retrieve
                         </code></pre>
                     </section>
+
+                    <section>
+                        <h5>Decorators mais comuns:</h5>
+
+                        <ul>
+                            <li><code>@property</code></li>
+                            <li><code>@staticmethod</code></li>
+                        </ul>
+                    </section>
+
+                    <section>
+                        <h5><code>@property</code></h5>
+
+                        <pre><code class='hljs'>
+&gt;&gt;&gt; class CheckConn(object):
+&gt;&gt;&gt;    def __init__(self, func):
+&gt;&gt;&gt;        self._func = func
+&gt;&gt;&gt;
+&gt;&gt;&gt;    @property
+&gt;&gt;&gt;    def func(self):
+&gt;&gt;&gt;        return self._func
+&gt;&gt;&gt;
+&gt;&gt;&gt;    @func.setter
+&gt;&gt;&gt;    def func(self, value):
+&gt;&gt;&gt;        self._func = func
+                        </code></pre>
+                    </section>
+
+                    <section>
+                        <h5><code>@staticmethod</code></h5>
+
+                        <pre><code class='hljs'>
+&gt;&gt;&gt; class CheckConn(object):
+&gt;&gt;&gt;    def __init__(self, func):
+&gt;&gt;&gt;        self._func = func
+&gt;&gt;&gt;
+&gt;&gt;&gt;    @staticmethod
+&gt;&gt;&gt;    def from_text(self, text):
+&gt;&gt;&gt;        return CheckConn(getattr(self, text))
+                        </code></pre>
+                    </section>
                 </section>
 
 				<section>
@@ -1195,6 +1236,57 @@ Julio
 					</section>
 				</section>
 
+                <section>
+                    <section>
+                        <h3>Context Managers</h3>
+
+                        <p>
+                            <i>Context Managers</i> são usados como "marcadores"
+                            para entrada e saída de pontos específicos.
+                        </p>
+                    </section>
+
+                    <section>
+                        <h3>Context Managers</h3>
+
+						<pre><code class="hljs">
+&gt;&gt;&gt; class Connection(object):
+&gt;&gt;&gt;    def __init__(self):
+&gt;&gt;&gt;        self._conn = None
+&gt;&gt;&gt;
+&gt;&gt;&gt;    def __enter__(self):
+&gt;&gt;&gt;        self._conn = self._make_connection()
+&gt;&gt;&gt;        return self._conn
+&gt;&gt;&gt;
+&gt;&gt;&gt;    def __exit__(self, exc_type, exc_value, traceback):
+&gt;&gt;&gt;        self._conn.close()
+&gt;&gt;&gt;        if exc_type:    # then exc_value and traceback
+&gt;&gt;&gt;            print "Exception!", exc_type, exc_value
+&gt;&gt;&gt;            print traceback
+						</code></pre>
+
+						<pre><code class="hljs">
+&gt;&gt;&gt; with Connection() as connection:
+&gt;&gt;&gt;     connection.request('Value')
+						</code></pre>
+                    </section>
+
+                    <section>
+                        <h3>Context Managers vs Exceptions</h3>
+
+						<pre><code class="hljs">
+&gt;&gt;&gt; try:
+&gt;&gt;&gt;     conn = self._make_connection()
+&gt;&gt;&gt;     conn.request('value')
+&gt;&gt;&gt; finally:
+&gt;&gt;&gt;     conn.close()
+&gt;&gt;&gt; except Exception as exc:  # Bare exceptions are BAAAADDD!
+&gt;&gt;&gt;     print 'Exception!', exc
+						</code></pre>
+                    </section>
+
+                </section>
+
 				<section>
                     <section>
                         <h3>Docstrings</h3>